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      <ol class="breadcrumb"><li><a href="/">Home</a></li><li><a href='../../'>Howl Documentation (master branch)</a></li><li>Spec</li><li>Aux</li><li>Spec - howl.aux.destructor</li></ol>
      <div class="spec-group spec-group-1">&#x000A;&#x000A;<h1 id="howl.aux.destructor">howl.aux.destructor</h1>&#x000A;&#x000A;<h4 id="returns-an-object,-for-which-&lt;callback&gt;-is-called-when-it-is-collected">returns an object, for which &lt;callback&gt; is called when it is collected</h4>&#x000A;&#x000A;<pre class="highlight moonscript"><span class="n">callback</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nc">Spy</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">destructor</span><span class="w"> </span><span class="n">callback</span><span class="w">&#x000A;</span><span class="nb">collectgarbage</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">assert</span><span class="p">.</span><span class="n">is_true</span><span class="w"> </span><span class="n">callback</span><span class="p">.</span><span class="n">called</span></pre>&#x000A;&#x000A;<h4 id="passes-any-additional-arguments-given-to-the-callback">passes any additional arguments given to the callback</h4>&#x000A;&#x000A;<pre class="highlight moonscript"><span class="n">callback</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nc">Spy</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">destructor</span><span class="w"> </span><span class="n">callback</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s1">'foo'</span><span class="w">&#x000A;</span><span class="nb">collectgarbage</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">assert</span><span class="p">.</span><span class="n">same</span><span class="w"> </span><span class="n">callback</span><span class="p">.</span><span class="n">called_with</span><span class="p">,</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s1">'foo'</span><span class="w"> </span><span class="p">}</span></pre>&#x000A;&#x000A;<h4 id="each-destructor-is-unique">each destructor is unique</h4>&#x000A;&#x000A;<pre class="highlight moonscript"><span class="n">callback</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nc">Spy</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">other_callback</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nc">Spy</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">destructor</span><span class="w"> </span><span class="n">callback</span><span class="w">&#x000A;</span><span class="n">destructor</span><span class="w"> </span><span class="n">other_callback</span><span class="w">&#x000A;</span><span class="nb">collectgarbage</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">assert</span><span class="p">.</span><span class="n">is_true</span><span class="w"> </span><span class="n">callback</span><span class="p">.</span><span class="n">called</span><span class="w">&#x000A;</span><span class="n">assert</span><span class="p">.</span><span class="n">is_true</span><span class="w"> </span><span class="n">other_callback</span><span class="p">.</span><span class="n">called</span></pre>&#x000A;&#x000A;<h4 id="defuse()-disables-the-destructor">defuse() disables the destructor</h4>&#x000A;&#x000A;<pre class="highlight moonscript"><span class="n">callback</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nc">Spy</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">d</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">destructor</span><span class="w"> </span><span class="n">callback</span><span class="w">&#x000A;</span><span class="n">d</span><span class="p">.</span><span class="n">defuse</span><span class="o">!</span><span class="w">&#x000A;</span><span class="nb">collectgarbage</span><span class="o">!</span><span class="w">&#x000A;</span><span class="n">assert</span><span class="p">.</span><span class="n">is_false</span><span class="w"> </span><span class="n">callback</span><span class="p">.</span><span class="n">called</span></pre>&#x000A;</div>
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